1. Field of the Invention
The present invention relates generally to a balanced transmission cable connector, and particularly to a balanced transmission cable connector that is used for high speed signal transmission.
2. Description of the Related Art
As data transmission schemes for transmitting data, a normal transmission scheme using one wire for each set of data may be used, or a balanced transmission scheme using a pair of wires for each set of data may be used to simultaneously transmit a (+) signal that is to be transmitted and a (−) signal in an opposite direction of the (+) signal but of the same size. In the balanced transmission scheme, influence from noise may be reduced compared to the normal transmission scheme. Thus, the balanced transmission scheme is becoming increasingly popular. A balanced transmission cable connector used in the balanced transmission scheme includes a balanced transmission cable, a plug that is implemented at the end of the balanced transmission cable, and a shield cover that covers the plug portion. For example, the balanced transmission cable connector may be used for establishing connection between a computer and a server.
FIGS. 1 and 2 are diagrams illustrating a balanced transmission cable connector 10 according to the related art. It is noted that directions X1-X2, Y1-Y2, and Z1-Z2 correspond to width directions, length directions, and height directions, respectively.
FIG. 3 shows a configuration of a balanced transmission cable 20. As is shown in this drawing, the balanced transmission cable 20 has an outer coating 27 and a shield mesh wire 28 that forms a dual coated tube structure inside of which plural wire lines 21 are implemented. Each wire line 21 includes a pair of first and second coated signal wires 22-1 and 22-2, and a drain wire 25 that are accommodated inside a shield tube.
As is shown in FIG. 6, the first and second coated signal wires 22-1 and 22-2, and the drain wire 25 extend from the end of the shield tube, and the ends of the first and second coated signal wires 22-1 and 22-2 are processed so that first and second signal wires 23-1 and 23-2 are exposed. It is noted that the first and second coated signal wires 22-1 and 22-2, and the exposed first and second signal wires 23-1 and 23-2 make up a wire pair.
Referring back to FIGS. 1 and 2, the balanced transmission cable connector 10 includes a relay substrate 12 that is fixed at the Y1 side of a plug structure 11. The plural wire lines 21 extend from the end of the balanced transmission cable 20, and the first and second signal wires 23-1 and 23-2, and the drain wires 25 extend further from the shield tube of the respective wire lines 21 to be connected to Y1 side terminals of the relay substrate 12 through soldering. Shield covers 31 and 32 cover the plug structure 11, the relay substrate 12, and an end portion of the balanced transmission cable 20. In this balanced transmission cable connector 10, the plug structure 11, the relay structure 12, and the end portion of the balanced transmission cable 20 realize data transmission paths.
However, in the balanced transmission cable connector 10, problems exist with regard to shielding adjacent transmission paths from one another at the relay substrate 12. The relay substrate 12 includes wiring patterns that extend in the Y1-Y2 directions and are aligned in the X1-X2 directions at the top and bottom surfaces of the relay substrate 12. In such a configuration, it is difficult to adequately shield adjacent signal pairs from each other at the relay substrate 12 to obtain the same shielding effect as that realized at the plug structure 11.
In recent years and continuing, the transmission speed of signals being handled by computers and servers is accelerating, and in turn, influences on the transmission characteristics due to poor shielding at the relay substrate 12 are becoming a problem.